Power tool system including a multi-core cable with an electronic memory module

ABSTRACT

A power tool system comprises a portable power tool ( 10 ), a stationery control unit ( 11 ), and a multi-core cable ( 12 ) for communicating power and/or signals between the power tool ( 10 ) and the control unit ( 11 ), wherein the cable ( 12 ) is provided with an electronic memory module in the form a data chip for storing data relating to the identity and operation characteristics of the cable ( 12 ) as well as data concerning the compatibility of the power tool ( 10 ), the control unit ( 11 ) and the cable ( 12 ), wherein the data chip is arranged to register and accumulate the number power tool operations performed via the cable ( 12 ) and indicate when a predetermined limit for power tool operations as regards mechanical wear of the cable ( 12 ) is reached.

The invention relates to a power tool system comprising a portable powertool, a stationary control unit and a cable for interconnecting thepower tool and the control unit thereby communicating power to the powertool and/or signals between the control unit and the power tool.

In power tool systems of the above type there is a necessity that thecomponents of the system, i.e. the power tool, the control unit, and thecable, are compatible with each other to form an accurately and safelyworking system. A key component is the cable, which apart from the riskthat a cable of an incorrect type or size has been chosen in the firstplace, it is exposed to a mechanical wear during use of the power tooland, therefore, has a limited service life.

Accordingly, there is a need for a data informing means by which theidentity as well as operational characteristics of the cable areobtainable. It is also very much needed a possibility to get anautomatic check as to whether the components of the power tool systemare of the correct type and size for the intended tool application. Forinstance, it is important that the cable is of the correct type and isable to cope with the actual power load intended for powering the actualtool. It is also important that the cable meets the safety requirementsof various certifying bodies like U.L, Semko etc. The safety concernsnot only the operational safety of the power tool system but also safetyregarding distorsions from and to other equipment. Personal safety ofthe operator has of course also high priority. Using a cable of anincorrect type may cause serious accidents.

As mentioned above, multi-core cables interconnecting portable powertools and stationary control units are exposed to a certain mechanicalwear during use of the power tool, and since such cables are not onlyexpensive to replace but they are crucial for guaranteeing a safe andproper power tool operation. A breakdown of such a cable may cause adangerous situation for the operator. Also a cable break down oftenmeans a costly stop in production, especially at assembly lineoperations.

Typical use of power tool systems of the above described type is forscrew joint tightening operations and for grinding. Screw jointtightening with power tool systems of this type is very common atassembly lines in the motor vehicle industry.

The main object of the invention is to create a power tool system of theabove described type wherein a means is comprised for providing datarelating to the identification characteristics of the cable.

A further object of the invention is to create a power tool system inwhich data are obtainable relating to the compatibility of the powertool, the control unit and the cable.

A still further object of the invention is to provide a method and apower tool system by which a power tool connected multi-core cable maybe safely used to an extent where the service life of the cable could bemade use of to a high degree without risking a cable breakdown.

According to the invention, the above objects are achieved by providinga multi-core cable of a power tool system as stated in the claims.

By a memory module carried by the cable there is obtained a registrationand storing of the accumulated number of power tool operations performedvia the cable to be compared with a predetermined acceptable number oftool operations for the actual power tool application.

In the accompanying drawing there is schematically illustrated a powertool system according to the invention where a portable electric powertool 10 is connected to a control unit 11 via a multi-core cable 12. Thepower tool 10 is hand held for manual support in different operationpositions, whereas the control unit 11 is secured to a stationarynon-illustrated structure in a vicinity of the power tool working site.The cable 12 is connected to the power tool 10 and to the control unit11 by two connection pieces 13,14, and in one of these connection pieces13 there is provided an electronic memory module in the form of a datachip (not shown). This data chip may contain several data relating tothe identity and characteristics of the cable 12, including Model No.,Series No., manufacturing date as well as special data provided by theusers such as date of purchase, specific work site, service history etc.

The chip is also intended to continuously register and accumulate thenumber of performed power tool operations as well as lapsed time etc.When reaching a predetermined number of tool operations or active periodof time which is considered to be a safe limit from the mechanical wearpoint of view in the actual tool application, there is generated awarning signal. Then, the cable should be exchanged for a new one. Theused cable could be used further in an another application where themechanical wear is less intensive.

The cable 12 comprises a data bus by which the chip communicates withthe power tool 10 and the control unit 11, and by this communication thechip is able to react on differences in the type of power tool connectedto the cable and control unit.

1. A power tool system, comprising a portable-power tool, a stationaryprogrammable control unit, and a multi-core cable interconnecting thepower tool and the control unit for communicating power and/or signalsbetween the power tool and the control unit, wherein said cablecomprises an electronic memory module which is arranged to communicatewith the control unit and/or the power tool and to store data relatingto identification characteristics of the cable.
 2. The power tool systemaccording to claim 1, wherein said memory module is arranged to storedata informing of the compatibility of the cable with at least one ofthe power tool and the control unit.
 3. The power tool system accordingto claim 2, wherein the data stored in said memory module are read by atleast one of the power tool and the control unit, and a means isprovided for permitting power tool operation when the data concerningthe cable, the control unit and the power tool are within predeterminedlimits.
 4. The power tool system according to claim 1, wherein saidmemory module is arranged to store data relating to the accumulatednumber of tool operation cycles performed via the cable and to indicatewhen the accumulated number of operation cycles equals a predeterminedacceptable maximum number of tool operation cycles for the actual powertool application.
 5. The power tool according to claim 1, wherein saidcable comprises a data bus extending over the entire length of saidcable and arranged to communicate signals between the control unit, thepower tool and said memory module.
 6. The power tool system according toclaim 2, wherein said memory module is arranged to store data relatingto the accumulated number of tool operation cycles performed via thecable and to indicate when the accumulated number of operation cyclesequals a predetermined acceptable maximum number of tool operationcycles for the actual power tool application.
 7. The power tool systemaccording to claim 3, wherein said memory module is arranged to storedata relating to the accumulated number of tool operation cyclesperformed via the cable and to indicate when the accumulated number ofoperation cycles equals a predetermined acceptable maximum number oftool operation cycles for the actual power tool application.
 8. Thepower tool according to claim 2, wherein said cable comprises a data busextending over the entire length of said cable and arranged tocommunicate signals between the control unit, the power tool and saidmemory module.
 9. The power tool according to claim 3, wherein saidcable comprises a data bus extending over the entire length of saidcable and arranged to communicate signals between the control unit, thepower tool and said memory module.
 10. The power tool according to claim4, wherein said cable comprises a data bus extending over the entirelength of said cable and arranged to communicate signals between thecontrol unit, the power tool and said memory module.
 11. The power toolaccording to claim 6, wherein said cable comprises a data bus extendingover the entire length of said cable and arranged to communicate signalsbetween the control unit, the power tool and said memory module.
 12. Thepower tool according to claim 7, wherein said cable comprises a data busextending over the entire length of said cable and arranged tocommunicate signals between the control unit, the power tool and saidmemory module.